This application pertains to lubricants applied to magnet wire are utilized to facilitate the winding of magnet wire into coils and to allow magnet wire coils to be inserted into coil support slots without damage to the insulation. More particularly, this invention relates to an improved solid magnet wire winding lubricant which can be used both as an internal lubricant and an external lubricant and which is compatible with the new non-chlorinated refrigerants such as Du Pont's R134a FREON and their lubricants now expected to be used in hermetic systems throughout the world.
Magnet wire winding lubricants have been widely utilized in the past. Today, nearly all magnet wire utilized in coils is utilized with a magnet wire lubricant to ease the winding of magnet wire into coils. Magnet wire lubricants are used in the winding of both stator coils and rotor coils in the manufacture of electrical motors wherein a plurality of windings need to be stacked in metal coil support slots and considerable wire to wire and wire to slot frictional resistance is experienced. Magnet wire lubricants are used not only to reduce this friction, but to insure that the magnet wire coils can be wound and/or inserted into coil supports without damage to the insulation. Such magnet wire lubricants generally must be chemically inert so that the lubricant will not degrade the magnet wire insulation or change the composition of other materials within which it comes in contact, and be capable of being applied to magnet wire. In addition, those magnet wire winding lubricants used in hermetic systems must be soluble in and compatible with both the refrigerants and the compressor lubricants used in such systems.
Within the industry, there are now used both internal and external lubricants. Internal lubricants are those which are mixed as a component of the magnet wire enamel and applied to the wire as a superimposed enamel coating on the wire. Other lubricants are used as external lubricants and are applied as a superimposed coating over the base insulation of the magnet wire. In either case, the lubricant partially defines the exterior surface of the magnet wire such that it engages either other turns of the coil, or the structure of the coil support during winding of the coil. The purpose of the lubricant is to allow the coils to be wound and inserted into coil supports without undue stretching of the wire or damage to the insulation by conventional winding machines.
It is therefore highly desirable to provide new and improved solid magnet wire winding lubricants.
It is also highly desirable to provide new and improved solid magnet wire winding lubricants which can be utilized as internal lubricants.
It is also highly desirable to provide new and improved solid magnet wire winding lubricants which can be used as external lubricants.
Most of the lubricants now used are a paraffin, hydrogenated triglyceride and/or fatty ester based lubricant. These materials are not suitable nor compatible with the newly proposed chlorine free refrigerants, or their compressor oils throughout their operational range. With the change from chlorinated refrigerants, such as Du Pont's R-12 and R-22 to chlorine free refrigerants such as Du Pont's R134a, a change was made from mineral oil based compressor lubricants previously used with the chlorinated refrigerants to ester or ether based compressor lubricants. This change was mandated due to the fact that the chlorinated refrigerants were miscible with mineral oil, whereas the new chlorine free refrigerants are more polar and are not miscible with mineral oil and require a more polar lubricant.
While magnet wire winding lubricants based upon paraffins, hydrogenated triglycerides and fatty esters of fatty acids are compatible with mineral oils, the same are not compatible in the more polar compressor lubricants such as the EMKARATE and the MOBIL compressor lubricants which are thought to be an eutectic of pentaerythritol esters at about -50.degree. C.
It is therefore desirable to provide new and improved solid magnet wire winding lubricants which are chemically inert in the new chlorine free refrigerants and the new ester or ether based compressor lubricants, are soluble in both, yet can be applied as magnet wire coatings by conventional techniques, and will allow winding insertion with ease and minimal damage to the magnet wire insulation.
It is also highly desirable to provide new and improved solid magnet wire winding lubricants which possess good winding and insertion properties and minimize broken or stressed wires upon insertion.
Finally, it is highly desirable to provide new and improved solid magnet wire winding lubricants which have all of the above desired features.